// Copyright 2003-2005 Arthur van Hoff, Rick Blair
// Licensed under Apache License version 2.0
// Original license LGPL

package io.libp2p.discovery.mdns.impl.constants;

/**
 * DNS constants.
 *
 * @author Arthur van Hoff, Jeff Sonstein, Werner Randelshofer, Pierre Frisch, Rick Blair
 */
public final class DNSConstants {
  // http://www.iana.org/assignments/dns-parameters

  // changed to final class - jeffs
  public static final String MDNS_GROUP = "224.0.0.251";
  public static final String MDNS_GROUP_IPV6 = "FF02::FB";
  public static final int MDNS_PORT = Integer.getInteger("net.mdns.port", 5353);
  public static final int DNS_PORT = 53;
  public static final int DNS_TTL =
      Integer.getInteger("net.dns.ttl", 60 * 60); // default one hour TTL
  // public static final int DNS_TTL = 120 * 60; // two hour TTL
  // (draft-cheshire-dnsext-multicastdns.txt ch 13)

  public static final int MAX_MSG_TYPICAL = 1460;
  public static final int MAX_MSG_ABSOLUTE = 8972;

  public static final int FLAGS_QR_MASK = 0x8000; // Query response mask
  public static final int FLAGS_QR_QUERY = 0x0000; // Query
  public static final int FLAGS_QR_RESPONSE = 0x8000; // Response

  public static final int FLAGS_OPCODE = 0x7800; // Operation code
  public static final int FLAGS_AA = 0x0400; // Authorative answer
  public static final int FLAGS_TC = 0x0200; // Truncated
  public static final int FLAGS_RD = 0x0100; // Recursion desired
  public static final int FLAGS_RA = 0x8000; // Recursion available

  public static final int FLAGS_Z = 0x0040; // Zero
  public static final int FLAGS_AD = 0x0020; // Authentic data
  public static final int FLAGS_CD = 0x0010; // Checking disabled
  public static final int FLAGS_RCODE = 0x000F; // Response code

  // Time Intervals for various functions

  public static final int SHARED_QUERY_TIME = 20; // milliseconds before send shared query
  public static final int QUERY_WAIT_INTERVAL = 225; // milliseconds between query loops.
  public static final int PROBE_WAIT_INTERVAL = 250; // milliseconds between probe loops.
  public static final int RESPONSE_MIN_WAIT_INTERVAL = 20; // minimal wait interval for response.
  public static final int RESPONSE_MAX_WAIT_INTERVAL = 115; // maximal wait interval for response
  public static final int PROBE_CONFLICT_INTERVAL = 1000; // milliseconds to wait after conflict.
  public static final int PROBE_THROTTLE_COUNT = 10; // After x tries go 1 time a sec. on probes.
  public static final int PROBE_THROTTLE_COUNT_INTERVAL =
      5000; // We only increment the throttle count, if the previous increment is inside this
  // interval.
  public static final int ANNOUNCE_WAIT_INTERVAL = 1000; // milliseconds between Announce loops.
  public static final int RECORD_REAPER_INTERVAL = 10000; // milliseconds between cache cleanups.
  public static final int RECORD_EXPIRY_DELAY =
      1; // This is 1s delay used in ttl and therefore in seconds
  public static final int KNOWN_ANSWER_TTL = 120;
  public static final int ANNOUNCED_RENEWAL_TTL_INTERVAL =
      DNS_TTL * 500; // 50% of the TTL in milliseconds
  public static final int FLUSH_RECORD_OLDER_THAN_1_SECOND =
      1; // rfc6762, section 10.2 Flush outdated cache (older than 1 second)

  public static final int STALE_REFRESH_INCREMENT = 5;
  public static final int STALE_REFRESH_STARTING_PERCENTAGE = 80;

  public static final long CLOSE_TIMEOUT = ANNOUNCE_WAIT_INTERVAL * 5L;
  public static final long SERVICE_INFO_TIMEOUT = ANNOUNCE_WAIT_INTERVAL * 6L;

  public static final int NETWORK_CHECK_INTERVAL = 10 * 1000; // 10 secondes
}
